Over the years, many electronic instruments and devices have been sufficiently reduced in size to become portable, and in turn, small enough to be held and operated in the hand of the user. The advent of integrated circuits greatly increased the number of devices that could achieve portability and handheld status, as well as increasing the functionality of such devices.
Today, handheld data processing devices include computers, video displays, audio players and recorders, laboratory instruments, telephones and other communications devices. In many cases, multiple functions may be integrated into a single device such as in a telephone/audio player combination.
The data processing functions included in a handheld device may require a variety of input/output capabilities. Devices with audio signal processing capabilities require a microphone for input and/or a speaker for output. Tactile transducers such as keypads and touch panel displays are useful for general alphanumeric input to a wide variety of devices. Visual displays ranging from simple indicating lights to video displays capable of rendering a television broadcast may be found as the outputs on many handheld devices.
In addition to user input/output interfaces, devices may also have wireless transmitters and receivers. These wireless interfaces may use radio frequency, infrared, or visible portions of the electromagnetic spectrum.
The competing interests of increasing functionality and small size in handheld devices have led to compromises in the design of the fixed form factor packages that are used for most handheld devices. For example, devices such as calculators or personal digital assistants must allocate a fixed amount of available surface area to a display and a keypad.
Ergonomic constraints also play a key role in the design of fixed form factor handheld devices. The degree of miniaturization that can be applied to a keypad is typically limited by the size and dexterity of an average user's fingers. Likewise, the placement of a speaker and microphone for a telephone is limited by the mouth and ear separation of a typical user.
Fixed form factor handheld devices such have been supplemented by variable form factor devices having components connected by hinges. In general, hinges provide a more compact form factor for storage when closed, but the device is often not functional with the hinge in a closed position (e.g., a some handheld calculators).
Conventional placements of speakers, microphones, and keyboards (keypads) yielded larger PDA form factors and resulted in undesirable telephony experiences while also not addressing issues relating to an integrated display protection solution. Displays were left exposed and unprotected from debris and facial oils during phone usage. Many integrated keyboards are forced to fit within the width of a portrait-mode device, thus compromising ergonomics due to decreased key size and spacing. Further, earpiece to microphone separations were solely dictated by device size, whether too small or too large.
Thus, a need exists for an adjustable form factor for handheld devices that provides functionality in both extended and compact forms.